Pressure roller for pellet mill



March 3, 1959 H. s. LANDERS 2,875,709

PRESSURE ROLLER FOR PELLET MILL Filed Nov. 8, 1956 A Hill FIG. 2.

9 I Fla 5 HARVEY SMITH LANDERS INVEN TOR. BY wfilwq A TTORNEY UnitedStates Patent PRESSURE ROLLER FOR PELLET MILL Harvey Smith Landers, FortWorth, Tex. Applieation November 8, 195'6, Serial'No. 621, 175

3 Claims. (Cl. 107-14) This invention relates generally to pellet millequipment and more particularly to an improved device of this type forproducing compacted feed pellets.

The primary object of this invention is to provide a pressure roller fora pellet mill which will produce more satisfactory pellets with lesspressure against the die.

Another object is to provide a roller for use with a conventional feedpellet mill die whereby the roller will prevent the customary squeezingloss which occurs along the sides of the roller and die.

A further object is to provide a pressure roller which will increase thelife of both the roller and the die due to the evenly distributed pointof contact and traction between the two members.

And another object is to provide a pressure roller which together with afeed pellet mill die can handle feed having a much greater range ofmoisture or steam content than can be handled using a conventionalroller.

An additional object is to provide an improved pressure roller for usewith different pellet mill dies rather than requiring the presentmatched set method of operation and maintenance replacement.

And yet another object is to provide a pressure roller which has a bandof solid material at each lateral edge to engage a corresponding band ofsolid material on the mating die to both reduce edge wear and gainadditional production of the mill.

These and other objects will be apparent from an examination of thefollowing specification and drawing in which:

Figure 1 represents a top plan view of the improved pressure roller ofthis invention.

Figure 2 is an end view of the roller of this invention installed in aconventional pellet mill and showing a fragmentary cut-away sectionthrough the pellet mill die.

Figure 3 is a fragmentary cross sectional view taken along the lines3--3 of Figure 1.

Figure 4 is a fragmentary cross sectional view taken along the lines 4-4of Figure 2.

Figure 5 is an enlarged fragmentary view of a short section of Figure 3for showing the details of the roller dimples.

Figure 6 is a fragmentary view of a portion of Figure 2 while the millis in operation and showing the cooperating relationship of the rollerand die.

Referring now more particularly to the characters of reference on thedrawing, the roller 2 comprises a solid center ring 3 of materialsuitable for subsequent case hardening and a reduced diameter to formend sections 4 and which has closely machined inner diameters to formbearing seats 5, spacer groove 6, seal grooves 7, and retainer shoulders8. .Along the outer surface 9 there are drilled a multiplicity of shortdepth shallow holes or cavities 10 around the entire circumference ofroller 2 except near each edge of roller 2 whereat a small continuousband 11 of solid material is intentionally provided.

The arrangement shown in Figures 2, 4 and 6 is typi- 2,875,709 PatentedMar. 3, 1959 cal for many current feed pellet mills wherein the die '12'in cludesta plurality of pellet holes 13 which may be tapered at theirentrance 14 to facilitate compaction of the pellets 15. Die 12 issecured by capscrews 16 in a die drive plate 17 which is driven by apower mechanism (not shown) to impart rotation to die 12. Roller 2 isheld in close contact with die 12 by means of a for]; 18 and a strap 19.A pair of shafts 2f0 support opposed tapered roller bearings 21 whichare separatedby spacer 22in groove 6 and each shaft 20 engages aretainer 23 and stud 24 which in turn engages nut 25 to bind strap 19 inplace. A grease seal (not shown) may be installed in grooves 7, andbearings 21 are so installed that the inner race, shaft 20, retainer 23and plate 17 remain stationary while the outer race and roller 2 mayfreely rotate upon urging from the power driven die ring 12. The areabetween the inner circumference of die 12 and the outer circumference ofrollers 2 and 2 is known as the pelleting chamber 26 and the feedmaterial M to be pelleted is fed into this chamber from a feed spout(not shown). The material may in one instance be ground (powdered)livestock feed which is partially saturated with steam to give it thenecessary moisture content to bind together upon compaction. The powerrotation of die 12 as shown by the arrows (Figure 6) draws the loosebulk material M into the converging area between die 12 and roller 2 sothat it is forced into and through pellet holes 13 wherein it is furtherpressurized by passing through tapered entrance groove 14, and as die 12rotates further the exposed pellets 15 are cut off by knives 27 and dropdown into a conveyor or other means for packaging or storage.

At each edge of die 12 (Figure 4) there is a continuous band 28 which iswider than the corresponding mating band 11 of roller 2 to account forslight misalignments in a lateral direction. The roller 2 and die 12operate in a touch-control relation so that there is no room betweenbands 11 and 28 for material M to squeeze out laterally as is the commonoccurrence when using a corrugated roller having lateral bands. It willalso be noted that much less pressure is required to obtain satisfactoryoperation with the combination shown in Fig ure 4 than when using acorrugated (tooth) roller since the material M is under control ratherthan able to shoot out sideways by means of the exposed lateral bands.There is also no tendency for the edges of rollers to wear down inconventional corrugated dies. The entire outer circumference 9 may becase-hardened and polished after drilling is completed. to furtherincrease its wearability.

The invention is not limited to the exemplary construction herein shownand described, but may be made in various ways within the scope of theappended claims.

What is claimed is:

1. A pressure roller for a pellet mill comprising: a circular ringhaving a smooth circumferential outer surface, a band of solidcontinuous surface adjacent each lateral edge of said ring, and amultiplicity of short depth radially drilled tapered holes in said outersurface in closely spaced relationship between said bands, said outersurface being case hardened throughout its circumference.

2. In a pellet mill including a circular die having a plurality ofpellet holes radially disposed therein and including a support forretaining a pressure roller thereon for rotary motion and providing apower driven relationship between said die and roller; a rollercomprising a continuous outer circumferential surface for mating withthe inner circumferential surface of said die, said roller including acontinuous band at each lateral edge thereof, and a multiplicity ofshort depth radially drilled tapered holes in said outer surface betweensaid bands and in staggered rows of alignment between said bands, saidouter surface being hardened and polished throughout its circumference.

3. In a pellet mill including a circular die having a plurality ofpellet holes radially disposed therein and including a support forretaining a pressure roller thereon for rotary motion and providing apower driven relationship between said die and said roller; a rollercomprising a continuous outer circumferential surface for mating withthe inner circumferential surface of said die, said roller outercircumference including a band of continuous surface at each lateraledge thereof and a multiplicity of round cavities in said outercircumference between said bands, said cavities being arranged intransverse rows, the number of cavities in any one row being 4 v atleast equal to the transverse number of holes in said die.

534,071 Mitchell Feb. 12, 1895 1,467,883 Sizer Sept. 11, 1923 2,240,660Meakin May 6, 1941 2,295,743 Meakin Sept. 15, 1942 2,455,980 Dallas eta1. Dec. 14, 1948 2,596,159 McBirney May 13, 1952 2,670,697 Meakin Mar.2, 1954

